Photos of the Long Island Sound

Status and Trends: LISS Environmental Indicators

Type of Indicators: Health/Condition Response/Performance Socio-Economic Historical/Background

Toxic Contaminants

Industrial Chemical Discharges (TRI data – CT and NY)

This indicator compiles the total amount of discharges of toxic chemicals manufactured and used at industrial facilities that are released into the Sound either by air or by water. View Indicator

Wastewater Treatment Plants Meeting Toxicity Standards

Aquatic organisms are exposed to effluent from wastewater treatment facilities as a test for effluent toxicity. This indicator is the percentage of facilities in CT passing these tests. View Indicator

Contaminant Trends in Mussel Watch Sites

Mussels tend to stay in one location and feed by filtering particles out of the surrounding water. They can accumulate local contaminants such as metals and PCBs in their tissues. Measuring levels of contaminants in their tissue is a good indicator of local contamination. View Indicator

Sediment Quality Index

This index indicates the extent and severity of contaminants such as PCBs, hydrocarbons, metals, and pesticides in seafloor sediments throughout Long Island Sound. View Indicator

Heavy Metals in Sediment

Sediment cores were sampled near Norwalk Harbor to determine the historic trends of toxic contamination in the seafloor sediment of the Sound. The cores give a record of metal contamination from the pre-colonial period to the post-industrial era. View Indicator

Lead Concentrations in Sediment by Basin

This map shows the concentration of the heavy metal lead within the seafloor sediments throughout Long Island Sound. View Indicator

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